Brussels has ditched some of its antitrust action against Microsoft, after the software giant agreed to offer Windows customers a choice of web browsers via its operating system.

Microsoft will avoid further fines from regulators at the competition arm of the European Commission, if it gives Windows users a pop-up screen that lets EU customers decide which browser - such as Firefox or Google’s Chrome - to use on their computer.

"Millions of European consumers will benefit from this decision by having a free choice about which web browser they use," said EU Competition Commissioner Neelie Kroes.

"Such choice will not only serve to improve people's experience of the internet now but also act as an incentive for web browser companies to innovate and offer people better browsers in the future."

The vendor will be required to implement the option by mid-March, however the commitments it has made to the EC are “legally-binding” from today. The move means that computer makers will be able to ship Windows-based PCs without Internet Explorer to countries within the 27-state bloc.

Windows users will be provided with a "Choice Screen" containing the 12 most widely-used web browsers that run on the OS. There will also be an option for OEMs and customers to switch off IE and make a different browser the default option in Windows.

Norwegian browser maker Opera, which brought its complaint against Microsoft tying Internet Explorer to Windows to the EC in December 2007, welcomed today's announcement.

“This is a victory for the future of the web. This decision is also a celebration of open web standards, as these shared guidelines are the necessary ingredients for innovation on the web,” said Opera CEO Jon von Tetzchner

“Opera has long been at the forefront of web standards, which ensures that people have equal access to the Web anytime, anywhere and on any device. We see the outcome of the EU’s investigation as a testament to our mission.”